cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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rpmsg_ns.c (3240B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) STMicroelectronics 2020 - All Rights Reserved
      4 */
      5#include <linux/device.h>
      6#include <linux/kernel.h>
      7#include <linux/module.h>
      8#include <linux/rpmsg.h>
      9#include <linux/rpmsg/ns.h>
     10#include <linux/slab.h>
     11
     12#include "rpmsg_internal.h"
     13
     14/**
     15 * rpmsg_ns_register_device() - register name service device based on rpdev
     16 * @rpdev: prepared rpdev to be used for creating endpoints
     17 *
     18 * This function wraps rpmsg_register_device() preparing the rpdev for use as
     19 * basis for the rpmsg name service device.
     20 */
     21int rpmsg_ns_register_device(struct rpmsg_device *rpdev)
     22{
     23	rpdev->src = RPMSG_NS_ADDR;
     24	rpdev->dst = RPMSG_NS_ADDR;
     25
     26	return rpmsg_register_device_override(rpdev, "rpmsg_ns");
     27}
     28EXPORT_SYMBOL(rpmsg_ns_register_device);
     29
     30/* invoked when a name service announcement arrives */
     31static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
     32		       void *priv, u32 src)
     33{
     34	struct rpmsg_ns_msg *msg = data;
     35	struct rpmsg_device *newch;
     36	struct rpmsg_channel_info chinfo;
     37	struct device *dev = rpdev->dev.parent;
     38	int ret;
     39
     40#if defined(CONFIG_DYNAMIC_DEBUG)
     41	dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1,
     42			 data, len, true);
     43#endif
     44
     45	if (len != sizeof(*msg)) {
     46		dev_err(dev, "malformed ns msg (%d)\n", len);
     47		return -EINVAL;
     48	}
     49
     50	/* don't trust the remote processor for null terminating the name */
     51	msg->name[RPMSG_NAME_SIZE - 1] = '\0';
     52
     53	strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
     54	chinfo.src = RPMSG_ADDR_ANY;
     55	chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr);
     56
     57	dev_info(dev, "%sing channel %s addr 0x%x\n",
     58		 rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY ?
     59		 "destroy" : "creat", msg->name, chinfo.dst);
     60
     61	if (rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY) {
     62		ret = rpmsg_release_channel(rpdev, &chinfo);
     63		if (ret)
     64			dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret);
     65	} else {
     66		newch = rpmsg_create_channel(rpdev, &chinfo);
     67		if (!newch)
     68			dev_err(dev, "rpmsg_create_channel failed\n");
     69	}
     70
     71	return 0;
     72}
     73
     74static int rpmsg_ns_probe(struct rpmsg_device *rpdev)
     75{
     76	struct rpmsg_endpoint *ns_ept;
     77	struct rpmsg_channel_info ns_chinfo = {
     78		.src = RPMSG_NS_ADDR,
     79		.dst = RPMSG_NS_ADDR,
     80		.name = "name_service",
     81	};
     82
     83	/*
     84	 * Create the NS announcement service endpoint associated to the RPMsg
     85	 * device. The endpoint will be automatically destroyed when the RPMsg
     86	 * device will be deleted.
     87	 */
     88	ns_ept = rpmsg_create_ept(rpdev, rpmsg_ns_cb, NULL, ns_chinfo);
     89	if (!ns_ept) {
     90		dev_err(&rpdev->dev, "failed to create the ns ept\n");
     91		return -ENOMEM;
     92	}
     93	rpdev->ept = ns_ept;
     94
     95	return 0;
     96}
     97
     98static struct rpmsg_driver rpmsg_ns_driver = {
     99	.drv.name = KBUILD_MODNAME,
    100	.probe = rpmsg_ns_probe,
    101};
    102
    103static int rpmsg_ns_init(void)
    104{
    105	int ret;
    106
    107	ret = register_rpmsg_driver(&rpmsg_ns_driver);
    108	if (ret < 0)
    109		pr_err("%s: Failed to register rpmsg driver\n", __func__);
    110
    111	return ret;
    112}
    113postcore_initcall(rpmsg_ns_init);
    114
    115static void rpmsg_ns_exit(void)
    116{
    117	unregister_rpmsg_driver(&rpmsg_ns_driver);
    118}
    119module_exit(rpmsg_ns_exit);
    120
    121MODULE_DESCRIPTION("Name service announcement rpmsg driver");
    122MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
    123MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
    124MODULE_LICENSE("GPL v2");